Two new eremophilane Sesquiterpenoides from Ligularia dictyoneura

Two new eremophilane sesquiterpenoides, 6 alpha,9 alpha-dihydroxyeremophilenolide (1), and 1 beta,10 beta-dihydroxyeremophilenolide (2), along with ten known eremophilane sesquiterpenoides (3-12) were isolated from the aerial parts of Ligularia dictyoneura (Franch.) Hand.-Mazz. Their structures were elucidated by means of extensive spectroscopic analysis. Compounds 3-6 were assessed for their cytotoxicity against five human cancer cell lines (HL-60, SMMC-7721, A-549, MCF-7 and SW-480), and the result showed that they had no activity.